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| PD21 EXPERIMENT, RESPONSIBLE: Andrea Wulzer |
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PHENOMENOLOGY OF FUNDAMENTAL INTERACTIONS,
WITHIN AND BEYOND THE STANDARD MODEL
This project is centered on the phenomenology of the
fundamental interactions, within and beyond the Standard
Model. Specific investigations are carried out on the
following topics: radiative corrections in the Standard
Model; supersymmetric and grand unified models;
models with extra dimensions; phenomenology of neutrino
oscillations and structure of the lepton and quark mass
matrices; flavour and CP violation; astroparticle physics
and cosmology.
The main topics under recent investigation are listed below.
1) RADIATIVE CORRECTIONS IN THE STANDARD MODEL
* Analysis of the Standard Model contributions to the
anomalous magnetic moments of leptons. Comparison between
theoretical results and experimental data. Determination
of the fine-structure constant.
* Computation of two-loop corrections to Higgs boson
production and decays.
2) NEUTRINO PHENOMENOLOGY AND MODELS
* Construction and analysis of models for lepton masses with
maximal atmospheric mixing angle and large solar mixing angle.
Realizations with discrete flavour symmetries in four or
more dimensions.
3) SUPERSYMMETRIC EXTENSIONS OF THE STANDARD MODEL
* Flavour and CP violation in the quark and lepton sectors
in supersymmetric models. Experimental signals.
Connections with neutrino masses, leptogenesis, grand
unification.
* Supersymmetric QCD corrections to electric and magnetic dipole
operators in the MSSM. The case of Minimal Flavor Violation.
* Supersymmetric models with super-heavy scalars and finely-tuned
electroweak scale (`split supersymmetry'). Implications for
collider phenomenology, electric dipole moments and dark matter.
4) STRING AND FIELD THEORIES WITH EXTRA DIMENSIONS
* Superstring compactifications with fluxes and their
effective supergravity theories. Supersymmetry breaking,
moduli stabilization, phenomenological implications.
* Grand unified models with extra dimensions: gauge coupling
unification, proton decay, localization of fermions.
* Supersymmetry breaking and restoration in five-dimensional
theories.
* Graviton effects at colliders in theories with large extra
dimensions.
* Higgsless models with one TeV-scale extra dimension and
their deconstructed versions. Electroweak breaking,
unitarity, compatibility with precision electroweak data.
5) OTHER EXTENSIONS OF THE STANDARD MODEL
* Extensions of the Standard Model with two Higgs doublets
and gauge singlets. Symmetry breaking and observability of
the phases of the system.
6) COSMOLOGY AND ASTROPARTICLE PROBLEMS
* Inflationary models of the early universe, cosmological
perturbations, non-gaussian features. Cosmological models
with or without dark energy. Interactions between dark
matter and dark energy. Dark matter candidates: abundance
and detection. Leptogenesis.
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PHENOMENOLOGY OF FUNDAMENTAL INTERACTIONS, WITHIN AND BEYOND THE STANDARD MODEL
This project is centered on the phenomenology of the fundamental interactions, within and beyond the Standard Model. The main subjects of our investigation are: radiative corrections in the Standard Model; supersymmetric and grand unified models; models with a strongly interacting Higgs sector and/or with extra dimensions; phenomenology of neutrino oscillations and structure of the lepton and quark mass matrices; flavour and CP violation; astroparticle physics and cosmology.
The main topics of our recent research are listed below.
1) PHYSICS BEYOND THE STANDARD MODEL
* Characterisation of Higgs couplings: custodial breaking couplings and LHC constraints; low-energy theorems in double Higgs production of a composite Higgs; anomalous t tbar hh coupling in double Higgs production; strongly-coupled Higgs with a Minimal Flavor violating ansatz; the effect of new spin-one resonances responsible for the unitarization of the vector boson scattering amplitude; implications of a light sgoldstino on the Higgs physics.
* Vector boson scattering: theoretical study of the validity of the effective vector boson approximation.
* Study of spin-1composite resonances at LHC in a 4-site model supplemented by a composite Higgs. The charged di-boson production is analyzed. The issue of interference effects is faced for extra W' searches.
* Simplified description of composite Higgs models in 4D and implications of light Higgs boson mass for LHC.
* Lepton flavour: construction and analysis of models for lepton mixing angles, based on discrete symmetries and on grand-unified scenarios.
* New realisations of flavour structure in composite Higgs models.
2) RADIATIVE CORRECTIONS AND HIGH ORDER PROCESSES
* Anomalous magnetic moment of leptons: improved bound on new-physics contribution to the electron g-2, through new measurements of a_e and more refined determinations of alpha; possible measurement of the tau g-2.
* New Methods for Scattering Amplitudes: an improved version of integrand-reduction method for one-loop amplitudes; extension of the one-loop integrand decomposition to higher-rank integrand; progresses in multi-loop integrand reduction.
3) COSMOLOGY AND ASTROPARTICLE PROBLEMS
Study of the growth of cosmological perturbations in the non-linear regime, development of a new approach to the resummation of perturbative contributions at infinite orders, based on time-dependent evolution equations for the matter power spectrum for the density and the velocity field.
4) EFFECTIVE SUPERGRAVITY THEORIES
Study of the spontaneous braking of N=8 supergravity, in the hope of grasping some new qualitative aspect on the breaking of the EW symmetry and on the Hierarchy Problem. |
Istituto Nazionale di Fisica Nucleare - Piazza dei Caprettari, 70 - 00186 Roma
tel. +39 066840031 - fax +39 0668307924 - email: presidenza@presid.infn.it
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